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Utah State University

2009

Theses/Dissertations

Environmental Sciences

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard Dec 2009

Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digital soil mapping (DSM) relies on quantitative relationships between easily measured environmental covariates and field and laboratory data. We applied innovative sampling and inference techniques to predict the distribution of soil properties, soil attributes, taxonomic classes, and dominant vegetation across a 30,000-ha complex Great Basin landscape in southwestern Utah. This arid rangeland was characterized by rugged topography, diverse vegetation, and intricate geology. Environmental covariates calculated from digital elevation models (DEM) and spectral satellite data were used to represent factors controlling soil development and distribution. We investigated optimal sample size and sampled the environmental covariates using conditioned Latin Hypercube Sampling (cLHS). …

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Watershed-Scale Analysis Of Riparian Buffer Function, Molly Van Appledorn May 2009

Watershed-Scale Analysis Of Riparian Buffer Function, Molly Van Appledorn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability of riparian buffers to filter undesirable nutrients from upland sources has long been recognized as an important ecosystem service for maintaining or improving water quality, and as a result, many land management strategies have been built around the preservation or restoration of buffer zones. Newly derived flow-path metrics have shown great promise as a way to assess riparian buffer function at the watershed scale but a thorough investigation of metric performance was necessary. The goals of this study were to: 1) test the independence of flow-path metrics from traditional metrics using a spatially extensive, independent sample of watersheds, …

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Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie May 2009

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …

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Predicting The Growth Potential Of A Shallow, Warm-Water Sport Fishery: A Spatially Explicit Bioenergetics Approach, Samuel Kirk Dahle May 2009

Predicting The Growth Potential Of A Shallow, Warm-Water Sport Fishery: A Spatially Explicit Bioenergetics Approach, Samuel Kirk Dahle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Capturing the range of fish consumption and growth potential of large, heterogeneous lentic systems can be challenging due to strong gradients in productivity, the diversity of habits types present, and in some cases, site-specific water quality issues. Cutler Reservoir (Utah, USA) displays a high degree of spatial and temporal variation in physical conditions and potential water quality limitations for fish, including high summertime water temperature and large, diel fluctuations in dissolved oxygen concentrations. The combination of bioenergetics modeling and GIS spatial analysis offers a promising interface for quantifying the fish consumptive and growth potential across a spatially and temporally heterogeneous …

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Nitrogen Transport, Transformation And Cycling Through A Mountain Lake, Bull Trout Lake, Idaho, Usa, Ryan Settle Lockwood May 2009

Nitrogen Transport, Transformation And Cycling Through A Mountain Lake, Bull Trout Lake, Idaho, Usa, Ryan Settle Lockwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of a mountain lake on nitrogen dynamics in a sub-alpine watershed were examined via watershed monitoring, mesocosm experiments, microcosm experiments, and enzymatic assays during spring and summer of a single year. Our study addressed the questions: (1) How does hydrologic transport through the lake affect the net fluxes of dissolved nitrogen (N) species? (2) What are the net effects of the littoral zone biota on dissolved N fluxes? (3) What are the seston and benthic uptake rates of nitrate? (4) What is the magnitude of N retention in littoral zone sediments? (5) What role does microbial hydrolysis of …

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Measurement And Modeling Of Reduced-Gravity Fluid Distribution And Transport In Unsaturated Porous Plant-Growth Media, Robert Heinse May 2009

Measurement And Modeling Of Reduced-Gravity Fluid Distribution And Transport In Unsaturated Porous Plant-Growth Media, Robert Heinse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of reduced gravity on the balanced management of liquid, gaseous and ionic fluxes in unsaturated porous media remains a central challenge for plant-based bio-regenerative life support systems needed for long-duration space missions. This research investigated how shifting capillary and gravitational forces alter the sample-scale transport and distribution of fluids in mm-sized porous ceramic aggregates. Measurements in variably saturated media conducted on the International Space Station in microgravity (~1⋅10-3 gearth) and measurements during parabolic flight in variable gravity encompassing microgravity, terrestrial gravity and hypergravity (~1.8gearth) were supported by numerical modeling based on fundamental, …

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Exploring The Spawning Dynamics And Identifying Limitations To The Early Life-History Survival Of An Important, Endemic Fish Species, Sara Elizabeth Seidel May 2009

Exploring The Spawning Dynamics And Identifying Limitations To The Early Life-History Survival Of An Important, Endemic Fish Species, Sara Elizabeth Seidel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For many native, imperiled salmonid species, the prioritization of recovery and conservation efforts hinges upon the identification of a species most limiting life stage. The early life-history stage can be a limiting life stage for fish, and given the importance of the reproductive stage to overall persistence, there is a need to better understand the spawning ecology and early life history of many salmonids. The Logan River, in northern Utah, contains one of the largest metapopulations of imperiled Bonneville cutthroat trout (BCT) throughout the Bonneville Basin. Little research has evaluated the temporal and spatial distribution of BCT spawning nor quantified …

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The Pliocene/Pleistocene Evolution Of The Western Snake River Plain Near Grand View Idaho, Meagan R. Deraps May 2009

The Pliocene/Pleistocene Evolution Of The Western Snake River Plain Near Grand View Idaho, Meagan R. Deraps

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Western Snake River Plain provides us with a unique opportunity to study the evolution of basaltic volcanism. In addition to studying the horizontal variation at the surface of the plain, erosion by the Snake River also allows the study of the vertical variation. With the aid of a USGS EDMAP grant we mapped the Dorsey Butte quadrangle and southern half of the Little Joe Butte quadrangle at a scale of 1 :24,000. The quadrangles are located within both the Ada and Elmore counties of southwestern Idaho, approximately 30 km west of Mountain Home and 2 km north of Grand …

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